Check valve



Nm N mm o.

Inventor.

Ezra E. Cldrk E. E. CLARK CHECK VALVE Filed Aug. 22, 1927 Jan. 15, 1929.

Patented Jan. 15, 1929.

"EZRA E. CLARK, OF NEWTONVILLE, MASSACHUSETTS.

CHECK VALVE.

Application filed August 22, 1927. Serial No. 214,460.

,This invention relates to ehe'fl valves and has for one ol its ohjeets to provide a novel eheelt valve structure arranged soV that it may he loriied in closed relation from a point remote from the ehe-cl; valve and may be also releaserfl from said poi Another object of the invention is to provide a check valve structure arranged to be locked in closed relation by hydraulic means which may he controlled trom a reinrgc poii'rt.

Other olriects ole the invention are to iniprove generally (heck valves in theinlrtieulars lierinafter set forth.

In the preferred embodiment el? my invention I employ two connected check valves havingl a tandem arrangement, the valve zuldiaeent the supply or inlet end beine' larger than the other valve, and I provide for building' up a pressure in the space between said check valves, which pressure acte dit erentially on 'the check valves owing,l to their `dilierent sizes and thus locks them iu closed relation. i

y In order to give an understandino1 of the invention I have illustrated in the drawings a selected embodiment thereofv which will now be described after which the nove-lier tures Will be pointed out in the appended claims. y

The drawings shouv a sectional view of a check valve embodying my invention.

In the drawing l and .2 indicate two pipe sections of the length of pipe in which the check valve incorporated, 1 heine' at the inlet end and :2 at the, discha fe end My improved check valve comprises a casing; il having' an inlet 4 cominunicating with the pipe section l and a discharge or outlet 5 comnuinicating with the pipe scetiou EL said casing also havingf :i waterway (i extending' therethrough lu-tvseen the inlet and the outlet. The casino' is turther provided with two valve seats 'i' and il arranged in the Waterway, the valve seal: T which is adjacent the inlet being larger than the valve seat 8 which is adjacent the outlet 5.

9 is a olapper adapted to seat on the valve seat 7, said clapper being' herein shown as carried by an arm l0 which is pivoted to the casing at 11. This valve clapper is designed normally to open freely to allow fluid to flow from the inletto the outlet but is intended to close automatically to prevent a back flow.

(lo-operating with the valve seat 8 is a second valve clapper 11 which is shown as i pivote/d to the valve casing at The two clappers are connected by a link 13 which is pivoted to the clapper 9 at 14 and to the clapper 11 at l5. Said clappers thus have a tandem arranfrgement and are connected so that they open and close simultaneously.

In order to permit both valve clappers to Seat properly notwithstanding their heini: connected together I propose to malte one ot them (the chipper 9 in this embodiment) with a flexible peripheral iap lll uhifh eugages the seat 7, such llap providing;l a viel ding portion will lit ag the seat `i" ndfwithstandiner the fact that the elapper 9 connected to the other clapper 11.

Under normal conditions the valve clappers will function as an ordinary cheek valve in` allowing Water orxlluid to flow from the inlet to the outlet but they will automatically close to prevent back flow. Y

It is sometimes desirable to lock the clapper 9 closed so as to prevent. any flow ot' Water from the inlet to the outlet and iu accordance with the present invention this is accomplished by building' up a pressure in the chamber 17 between the two clappers which is greater than the pressure on the inlet side of the check valve and `which acts differentially against the clappers owingto their dili'erent sizes to hold the clapper 9 closed.

The desired pressure may be produced in the chamber 1T in any suitable Way. Said chamber is shown as having an inlet pipe 18 leading `thereinto which extends to a pump of suitable type indicated at 19 and by which water under `pressure mayY he pumped into the chamber 17. Since the opening through the valve seat 7 is larger than that through the valve seat S the pressure produced in the chamber 17 will exert a `greater torce on the clapper 9 tendiner to hold it closed than on the elappe ll lending to open it and this differential pressure will thus act to hold both clappers closed.

The pump or other apparatus by which the pressure in the chamber 17is controlled may be situated at a point remote from the check valve and thus the locking of the clappers in closed position may be accomplished from said remote point.

Under normal conditions the clappers Will be closed onto their seats by gravity and will only open as water is being` drawn from the outlet. It it is desired to look the valve closed for any reason itis simply necessary to operate the pump 19 and thereby produce in the Chamber 17 the desired pressure whieh will aet dilferentially on the elappers as above described thus looking' them Closed. The elappers will remain Closed so long* as the proper pressure is maintained in the chamber 17. There may also be established by this procedure a rone ot' higher pressure in the Chamber 1T which will prevent the liow oi any water :trom the outlet 2 bach through the inlet in ease the valve leaked by reason oi the elappers not being tightly seated.

1n order to provide tor the release ot the elappers when it is desi ed to permit water to'l'low through the cheek valve l have herein shown the elapper 11 as provided with a small leak port 20 whieh will permit the pressures on opposite sides of the elapper 1l to become equalized gradually whenever the pump 19 is stopped. As soon as these pressures have been thus equalized the dit1- ,terential pressure on the elapper 9 will be destroyed and said elappers Vwill function in their normal way to allow water to tlow from the inlet to the outlet as needed.

The lealr port 2O is sutlieiently smaller than the pipe 18 so that so long as the pump 19 is working the desired pressure may be maintained in the chamber 17 notwithstandingl the constant leak through the port 2t). Shortly after the pump stops, however, the pressures on opposite sides of the elapper 11 will be equalized as above described thus unlocking the Cheek valve.

The easing 3 may be made in various ways Without departing from the invention. For Convenience in manufacture and assembly I may make it in two sections 22, whieh are bolted together as shown at 23 to form the complete easing. Each section is shown as having one ot the valve seats therein and each section is also provided with a removable Cover 24- ivhioh when removed provides access to the interior of the easing. The making of the easing in the two sections simplifies manufacture and assembly but is not of importanee so tar as the invention is Concerned.

l Claim:

1. in a cheek valve structure, the Combination with a easinp` having` an inlet and an out-let and a waterway extending;` from the inlet to the outlet, said easing' havingq two valve seats therein, the valve seat which is nearest the inlet being larger than the other, of two eonneeted valve elappers arranged to be seated simultaneously on said valve seats, and means to build up a pressure in the space between said elappers, whereby the dilterw ential pressure on the Clapp/ers will hold them Closed.

2. In a cheek valve structure, the combination with a easingi having a waterway therethrough, ot two connected valve elappers in said Casing, one oi which is larger 'than the other, and means to build up a pres-'sure in the space between the elappers.` whereby. the ditlferential pressure thereon will hold them closed.

3. ln a eli-.eeh valve structure, the eo1nbination with a easing having' an inlet and an outlet, of two connected valre elappers therein arranged to open and close simultane` ously, the elapper nearest the inlet beine; larger than the other elapper, and means to build up and maintain in the space between the olappers a pressure greater than that on the inlet or outlet side of the elappers.

d. In a cheek valve structure, the combination with a easing` having an inlet and an outlet, et two Connected valve elappers there in arrangzed to be seated simultaneously, the elapper nearest the inlet being` larger than the other elapper, means to build up and maintain in the space between the elappers a pressure greater than that on the inlet side thereof, and means for automatically equalizingy the pressure on opposite sides of the elapper nearest the outlet when the valve is to be released.

ln testimony whereof, l have signed my name to this speeieation.

EZRA E. CLARK. 

